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Transient Charging Characteristics in Surface Flashover Development Process due to Explosive Electron Emission in Vacuum
Author(s) -
Nakano Yusuke,
Kojima Hiroki,
Tsuchiya Kenji,
Hayakawa Naoki
Publication year - 2015
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/eej.22739
Subject(s) - cathode , materials science , arc flash , field electron emission , electron , electric field , explosive material , transient (computer programming) , atomic physics , dielectric , surface charge , optoelectronics , electrical engineering , chemistry , physics , insulator (electricity) , organic chemistry , quantum mechanics , computer science , operating system , engineering
SUMMARY For the development of higher voltage vacuum circuit breakers and vacuum interrupters, surface discharge in a vacuum is one of the most significant issues. We measured the charge activity on alumina dielectrics in a vacuum through ultrahigh‐speed optical and electrical measurements. We found that surface flashover in a vacuum starts with an explosive electron emission (EEE) with higher current density, which consists of electron emission from the cathode, and results in surface flashover development. The transient charge on the alumina dielectrics formed by electrons emitted by EEE influences the distortion of electric field distribution around the cathode rod and then the subsequent flashover development. In particular, in the case of a shorter gap between the cathode rod and the alumina dielectrics, the electron emission may be suppressed by the relaxation effect of the electric field due to transient charge accumulation.